scholarly journals Advances in Synchrotron X-ray Polycrystalline Diffraction

1988 ◽  
Vol 41 (2) ◽  
pp. 101 ◽  
Author(s):  
William Parrish
Keyword(s):  
High Resolution ◽  
Grazing Angle ◽  
Anomalous Scattering ◽  
Wavelength Selection ◽  
High Count ◽  
Instrument Function ◽  
X Ray ◽  
Depth Analysis ◽  
Diffraction Patterns ◽  
New Applications

The advantages of synchrotron radiation for X-ray polycrystalline diffraction are illustrated by a number of examples. The plane wave parallel-beam X-ray optics uses a Si(lll) channel monochromator for easy wavelength selection and a set of long parallel slits to define the diffracted beam. The constant simple instrument function and the high resolution symmetrical profiles (FWHM 0.05") greatly simplify the data analysis and add a new dimension to profile broadening studies. The geometry permits uncoupling the 6-26 sample-detector relationship without changing the profile shape and makes possible new applications such as grazing angle incidence depth analysis of thin films. The same instrumentation is used for high resolution energy dispersive diffraction (BOD) by step-scanning the monochromator. The resolution is two orders of magnitude better than conventional BOD and can be used at high count rates. The easy wavelength selection yields diffraction patterns with the highest PI B and permits anomalous scattering studies.

Computer Simulation of Powder Patterns

1983 ◽  
Vol 27 ◽  
pp. 75-80
Author(s):  
W. Parrish ◽  
T. C. Huang ◽  
G. L. Ayers
Keyword(s):  
Computer Simulation ◽  
Powder Diffraction ◽  
Line Broadening ◽  
Instrument Function ◽  
X Ray ◽  
Profile Fitting ◽  
Fitting Algorithm ◽  
Diffraction Patterns

AbstractA method for computer simulation of X-ray powder diffraction patterns which are identical to those obtained experimentally is described. The calculated pattern is generated directly from the d's (or 2θs) and intensities of the phase(s) and is based on a profile fitting algorithm which uses the instrument function to form the profile shapes at all reflection angles. Examples of simulated patterns of mixtures, line broadening, linear and amorphous backgrounds, and counting noise are given.

Cryogenic Microcalorimeters for High Resolution Energy Dispersive X-Ray Spectrometry

1999 ◽  
Vol 5 (S2) ◽  
pp. 604-605
Author(s):  
J.Höhne ◽  
M. Altmann ◽  
G. Angloher ◽  
M. Bühler ◽  
F.v. Feilitzsch ◽  
...  
Keyword(s):  
High Resolution ◽  
Cryogenic Detectors ◽  
X Ray ◽  
Universal Detector ◽  
Detection Of Biomolecules ◽  
Electron Microscopes ◽  
Excellent Energy Resolution ◽  
New Applications ◽  
Scanning Electron Microscopes ◽  
The Universe

AbstractCryogenic detectors with excellent energy resolution and low energy threshold far beyond the level of semiconducting detectors open a variety of new. applications in physics including search for Dark Matter in the universe [2], neutrino physics [3], and IR-, UV- and X-ray astrophysics [4, 9]. Interdisciplinary fields where cryogenic detectors have already shown promising results are the detection of biomolecules [5] and X-ray spectroscopy at synchrotron beam lines [6] and in scanning electron microscopes (SEMs) [7]. For both, astrophysical and analytical use, the development of high resolution microcalorimeters based on iridium/gold phase transition thermometers and aluminum tunnel junctions for use in a compact and universal detector system was initiated.Our cryogenic microcalorimeters consist of an absorber, a temperature sensor and a weak coupling to a heat sink. An X-ray photon interacts with the absorber and raises its temperature. The sensor measures the temperature increase and the system then, mediated by the coupling, relaxes back to its operating temperature.

F-9 Progress with Silicon Drift Detectors Used for High Resolution—High Count Rate X-ray Spectroscopy

2004 ◽  
Vol 19 (2) ◽  
pp. 197-197
Author(s):  
H. Soltau ◽  
P. Lechner ◽  
G. Lutz ◽  
L. Strüder ◽  
C. Fiorini ◽  
...  
Keyword(s):  
High Resolution ◽  
Count Rate ◽  
High Count ◽  
High Count Rate ◽  
X Ray ◽  
Silicon Drift Detectors

Atomic structure of YB56 studied by digital high-resolution electron microscopy and electron diffraction

2001 ◽  
Vol 16 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Takeo Oku ◽  
Jan-Olov Bovin ◽  
Iwami Higashi ◽  
Takaho Tanaka ◽  
Yoshio Ishizawa
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Charge Coupled Device ◽  
X Ray ◽  
Resolution Electron ◽  
High Resolution Images ◽  
Diffraction Patterns ◽  
Simulated Images

Atomic positions for Y atoms were determined by using high-resolution electron microscopy and electron diffraction. A slow-scan charge-coupled device camera which had high linearity and electron sensitivity was used to record high-resolution images and electron diffraction patterns digitally. Crystallographic image processing was applied for image analysis, which provided more accurate, averaged Y atom positions. In addition, atomic disordering positions in YB56 were detected from the differential images between observed and simulated images based on x-ray data, which were B24 clusters around the Y-holes. The present work indicates that the structure analysis combined with digital high-resolution electron microscopy, electron diffraction, and differential images is useful for the evaluation of atomic positions and disordering in the boron-based crystals.

Update in a Rietveld analysis program for x-ray powder spectro-diffractometry

2003 ◽  
Vol 18 (1) ◽  
pp. 32-35 ◽  
Author(s):  
Yanan Xiao ◽  
Fujio Izumi ◽  
Timothy Graber ◽  
P. James Viccaro ◽  
Dale E. Wittmer
Keyword(s):  
Computer Program ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Analysis ◽  
Anomalous Scattering ◽  
Analysis Program ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Synchrotron Light ◽  
Diffraction Patterns

A computer program for refining anomalous scattering factors using x-ray powder diffraction data was revised on the basis of the latest version of a versatile pattern-fitting system, RIETAN-2000. The effectiveness of the resulting program was confirmed by applying it to simulated and measured powder-diffraction patterns of Mn3O4 taken at a synchrotron light source.

High-resolution TEM and XRD simulation of stacking disorder in 2:1 phyllosilicates

2008 ◽  
Vol 223 (01-02) ◽  
Author(s):  
Toshihiro Kogure ◽  
Jun Kameda
Keyword(s):  
High Resolution ◽  
Lateral Displacement ◽  
X Ray ◽  
Transmission Electron ◽  
Significant Difference ◽  
High Resolution Tem ◽  
Interlayer Region ◽  
Diffraction Patterns ◽  
Two Alternatives ◽  
Stacking Disorder

Stacking disorder is a common phenomenon in phyllosilicates but its nature is difficult to be deduced using conventional diffraction techniques. In contrast, recent investigations using high-resolution transmission electron microscopy (HRTEM) have elucidated the structure of stacking disorder in various phyllosilicates, by directly observing individual layers and stacking sequences. Furthermore, simulations of X-ray or electron diffraction patterns using the information from the HRTEM results can complement the limited analysis area in TEM and quantify the density of the stacking disorder.Although the bonding between adjacent layers is similar, there is a significant difference in the stacking disorder between two counterparts of dioctahedral and trioctahedral 2 : 1 phyllosilicates: pyrophyllite vs. talc and sudoite vs. trioctahedral chlorite. In pyrophyllite and sudoite, stacking disorder is caused mainly by two alternatives of the lateral displacement directions between the two tetrahedral sheets across the interlayer region. On the other hand, rotation of 2 : 1 layer is also an origin of the stacking disorder in talc and trioctahedral chlorite. This difference is explained by the corrugation of basal oxygen planes on the dioctahedral 2 : 1 layer formed by the tetrahedral tilting to enlarge

scholarly journals High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging

2013 ◽  
Vol 20 (6) ◽  
pp. 899-904 ◽  
Author(s):  
Atsushi Tokuhisa ◽  
Junya Arai ◽  
Yasumasa Joti ◽  
Yoshiyuki Ohno ◽  
Toyohisa Kameyama ◽  
...  
Keyword(s):  
High Resolution ◽  
High Speed ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Resolution Single

The Effect of Pb on the Interface Structure of Fe/Cr(100) Metallic Multilayers

2000 ◽  
Vol 648 ◽  
Author(s):  
Kyu-Young Kim ◽  
Masao Kamiko ◽  
Sang-Mun Oh ◽  
Guang-Hong Lu ◽  
Ryoichi Yamamoto
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Interface Structure ◽  
Metallic Multilayers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Interface Structures

AbstractWe investigated the differences in the interface structures and magnetotransport properties between surfactant-mediated multilayers and normal ones. From the observations of RHEED and High-Resolution X-ray diffraction patterns, we confirmed that the surfaces of Fe/Cr(100) multilayers with Pb are flatter and the interfaces are sharper than one without Pb, which means that Pb operates as an effective surfactant. The magnetoresistance(MR) ratio of the multilayers prepared with Pb was larger than that of the multilayers prepared without Pb. The change of resistance with magnetic field was larger for the multilayers with a surfactant.

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